Modeling of the Attenuation Effects of the Ionosphere and Troposphere for Radio Frequency Application

Current environment models employed in MDA simulations are, in general, not coordinated to present a globally consistent environment picture and can be based on functions that have not been updated to take advantage of the environment models and databases that have become freely available in the information age. In contrast, radar atmospheric effects models whose behavior is derived from globally consistent environment models and modern data sets can evaluate the probability of occurrence of adverse radar sensor effects enabling formal risk assessment and actionable results from environment modeling of the missile defense system. We propose developing a system of radar environment effects modules that anchor their behavior to global environment models such as the Standardized Atmosphere Generator (SAG), the International Reference Ionosphere (IRI), and the International Geomagnetic Reference Field (IGRF). In addition, probability of occurrence distributions will be developed from modern databases of environment observations such as GPS scintillation and TEC data. For ionospheric radar effects we will address scintillation, range delay, auroral clutter, and Faraday rotation/absorption. Current scintillation models in propmod rely on conventional solar and geomagnetic observables such as sunspot number and planetary K index, Kp. We plan to use results from our analysis of an extensive set.Approved for Public Release | 18-MDA-9522 (23 Feb 18)